Chair back construction



May 27, 1941.

J. E. BALES C HAIR BACK CONSTRUCTION Filed June 3, 1939 Patented May 27, 1941 CHAIR BACK CONSTRUCTION James E. Bales, Aurora, Ill., assignor to Lyon Metal Products, Incorporated, Aurora, Ill., a corporation of Illinois Application June 3, 1939, Serial No. 277,238

12 Claims.

This invention relates to chair constructions `and more particularly to chairs formed of metal.

The present invention relates to an improved back construction for a metal chair, and among the objects of the present invention are to provide a metallic chair having a metallic backing constructed and arranged automatically to flex to fit the back of a person sitting in the chair; to provide a folding chair having a back which is substantially coextensive with the back of a person seated in the chair, and which back is adapted automatically to assume the proper back pitch relatively to the seat when the chair is opened for use; to provide a folding chair having an upstanding back frame and pivotally connected front and back legs, together with -a seat pivota-lly connected to both of said front and back legs, and a chair lback constructed and arranged quickly to be assembled and/or removed from said back frame ,and rear legs, easily and economically to be maintained in assembled position with respect thereto and which is not only capable of flexing to t the back of a person seated in the :chair lbut which has an automatically shiftable connection with :a ch-annel shaped portion of the rear legs which will permit the back in connection with such legs to shift relatively thereto when the chair is collapsed or opened for storage or for use, and wherein, when opening, the shiftable connection between the back and the rear legs is adapted adjustably to rock or shift to permit the back to have the proper back pitch; to [provide a simple type `of back comprising a lower horizontal cross piece and a plurality of vertically disposed, connecting, flexible strips and an upper connected cross piece, which latter piece is adapted detachably to lit within an upper channel portion of the main frame of the chair, and which lower cross piece is :adapted detachably to slide within channeled portions of the rear legs; to provide a detachable and 'attachable back constructed and arranged to be quickly assembled in a standard type of channeled collapsible chair, and which back, when so assembled, will automatically flex and pivotally shift with respect to its mounting members to t the back of a person seated in the chair, and whereby likewise to permit the chairV to be collapsed, or unfolded for use; to provide, as an article of manufacture, .a back capable of being constructed as a solid sheet back, perforated sheet back, horizontal strips, ladder type back, or other constructions, and .adapted for attachment to channeled members of folding chairs, and which back extends substantially the full length of the back of a person seated in the chair, to support the same, `and which back, when connected to the frame members, is adapted to shift rel-atively to one of the leg members to permit the chair to fold and to assume proper back pitch when open; to provide these and other objects of invention as will be apparent from a perusal of the following specification when taken in connection with the accompanying drawing, wherein:

Fig. 1 is a perspective view of the improved back construction :as applied to .a type of chair forming the subject matter of .a prior pending application Fig. 2 is .a perspectiverview of the 4back as a separate article of manufacture;

Fig. 3 is a view in section taken on the line 3--3 of Fig. 1;

Fig. 4 is a sectional view showing the folded position of Fig. 3;

Fig. 5 is a Adetail sectional View taken on the line 5-5 of Fig. 1;

Fig. 6 is a detail sectional view taken on the line 6-6 of Fig. 1;

Fig. 7 is a detail sectional view taken on the line 'I-l of Fig. 3;

Fig. 8 is a `detail view taken on the line 8-8 of Fig. 6; and

Figs. 9 and 10 are details of modifications.

In illustrating and describing the present invention, I have shown the chair as comprising a main chair construction like that described and claimed in the pending application of John B. OConnor, Serial No. 170,256, filed October 2l, 1937. However, it `is to be understood that the mechanical features of the back, irrespective of the design of the back, may be utilized with other types of folding chair construction provided the same lend themselves to appropriate adaptation.

For the purposes of illustration I shall therefore describe the chair as applied to the speciiic construction referred to in the prior mentioned application, wherein the chair in general com- -prises a main frame formed from a metal channel bar I0, bent into substantially U-shape, and

braced at its lower end by -a cross brace II. A pair of channel bars I2 and I3, :connected by a cross brace I4, are pivotally secured at their upper ends to the channel bar ID and together f-orm a rear support frame for the chair. A seat I6 is pivotally secured Vto the main frame by `pivots Il and each rear corner of the seat is provided with a projection I8 carrying a cylindrical lug I9 slidable within its associated rear channel bar I2., Each of the channel bars carries a stop 20 for' limiting the upward movement of its associated lug. The lower ends of the channel bars carry rubber feet 2l affording a firm and solid supporting construction.

By virtue of the foregoing construction it will be seen that the chair is of the folding type and may be readily manipulated from its open or seating position, as shown in Figs. 1 and 3,'to its closed position, as shown in Fig. 4, for storage purposes. This operation may be readily effected by grasping the chair back and front of the seat and rotating the seat clockwise with respect to the frame about the pivots I'i. During this operation the rear support frame comprisingY the channels I2 and i3 will be moved into substantial engagement with the main frame channel Ill, and the seat will simultaneously be brought into the plane of the main frame whereby to collapse the chair construction. When it is desired again to open the chair to seating position, the seat is pivoted counterclockwise with respect to the frame, bringing the parts into the position illustrated in Fig. 1. During this operation the stops 2i) limit the upward movement vof the rear of the seat, thus holding the seat during use in firm, substantially horizontal position and against collapse.

Inasmuch as the details of the construction of the seat are fully shown and claimed in the prior mentioned application of John B. OC'onnor,

Serial No. 170,256, no further description thereof is necessary. The aforementioned construction is claimed in the prior mentioned case. .The main features of the present invention reside in the construction of the back, as shown in Fig. 2, and

particularly in the functional cooperation of this back with the channel members lil and I2 hereinbefore described.

The back of the present invention is constructed substantially of full length, whereby to support the entire back, including the small of the back, of the person seated in the chair, and in a manner such that the support will be a flexible one, automatically adjusting itself to the particular conformation of the seated person, and in such a manner that the mounting of the lower portion of the back rest may shift automatically with respect to the channel member I2 not only in the open position of the chair, as when a person sits therein, but also when the chair is collapsed to folded position. In addition, the yback is constructed so that it may quickly be removed or applied to the frame construction hereinbefore described, in the most expeditious and economical manner. Furthermore, the back is constructed of simple sheet metal parts, proiding maximum flexibility combined with requisite rigidity and support, and providing in addition a most ornate, simple and pleasing appearance.

Referring to the back construction, the same comprisesra lower cross brace 22 formed of sheet metal doubled upon itsehc in the manner illustrated in section in Fig. 6, and an upper cross member 2d of sheet metal and generally of U-shape in cross section, as shown clearly in Fig. 5. This member 2! is shorter on its upper surface, as at 25, than it is on its lower surface, and is formed slightly beveled at its upper ends, as at 28 and 3S, tot within the rounded upper portion of the channel member I6. At desired spaced points the channel U-shape member 24 is slotted, as at 32, to receive the bent ends of a plurality of vertically disposed, flexible, metal backing strips 34, the bottom ends of which pass through suitable spaced slots 36 in the .foldedA bottom cross strip 22. Rivets 38 hold these strips connected to the cross strip 22 and serve to assist in maintaining the folds of the cross strip together. Each one of the vertical strips 34 is formed as a single strip of flexible spring metal.

Means is provided for adjustably, pivotally and shiftably uniting the lower cross bar 22 Within the channel of the member I2, whereby the member 22 may shift with relation to the channel members I2 and i3. The specific means illustrated for this purpose comprises a cam-like member 49 formed of sheet metal and centrally slotted to permit each end 42 of the bar 22 to pass therethrough and to be bent thereover and `velded thereto, as shown in Fig. 8. In addition, the ends lili and 45 are bent in the manner shown in cross section in Fig. 8, so as to provide a minimum of resistance to movement of the ends relative to the channel shape leg members I2 and I3. In addition the opposite sides of these cam members D are slightly tapered in reverse directions from a central, substantially rounded portion, as shown at 48 and 50, whereby to provide opposed rocking faces for the ends of the bar 22 so that the bar may rock on these surfaces 48 and 5i! against the channel walls of the legs I2 and i3. In addition, by means of a screw 52, the upper cross bar 26 may detachably be held within the upper portion of the channel frame member lil.

Referring now particularly to the cooperation of the back construction with the general features of the chair frame, and particularly to Figs, 4 and 6, it will be noted that when the chair is moved from collapsed, closed position, as shown in Fig. 4, to the open position shown in Fig. 3, during the opening movement the cam shaped members 40 will have rocked in the channel shaped members I2 and I3 from the position shown in Fig. 4 to the position shown in Fig, 3, the rocking taking place about the pointsl 48 and 50 on the `sides of the channel. VIt will also be noted that the members 40 will slide downwardly in the channel shaped legmembers l2 and I3 to accommodate the opening movement of the legs. Conversely, when the chair is moved from open position to collapsed position, a substantially opposite rocking and sliding movement of the lugs 40 on the lower cross piece 22 will take place. When a person sits on the seat of the chair, when in the open position shown in Fig. 1, no rocking of the lug members 40 in the channel shaped bar 22 Will take place. However, it is at this instant that the flexibility of the vertical back strips 34 functions. By reference to Fig. 6, it will be noted that these strips, being of spring metal and being attached only at top and bottom, will be free to bow outwardly to accommodate themselves to the particular back conformation of the person sitting on the chair seat, so that the back ofY such person will be flexibly and resiliently supported throughout the entire length of the back. Furthermore it will be noted that the lower cross support 22, being held within the channel walls of the leg supports I2 and I3, will form a support for the back of the hips of theperson seated and will not permit them tobulge out rearwardly Vbeyond the rear edge of the seat I6. Also, when the seat is in open position, this lower cross brace V22 will be substantially in the same vertical plane with the rear edge of the seat, and the vertical strips 34 will extend in a general backwardly slant'ing position tothe point where they-connect with the upper cross brace 24 which is detachably conflned within the horizontal channel portion of the main frame l0.

It will thus be seen that I have provided a chair wherein the back is attached to the stationary top portion of the channel shaped member I and is likewise attached to the rear legs l2 and I3, which legs are pivotally and foldably connected to the frame member l0 and provide a connection which permits of shifting movement to allow the chair to be opened or closed, and wherein, in open position, the back will flexibly support and conform to the back of the person seated in the chair. Furthermore, in such a construction the back construction permits the seat snugly to fit in a substantially vertical and parallel plane with the main frame l0 and the leg portions I2 and I3, whereby the chair occupies a minimum of space. This is due to the fact that the cross bar 22 is not centrally disposed with respect to the lugs 40 but is disposed slightly to the rear thereof, as shown in Fig. 6.

In Figures 9 and 10 I have shown modifications of the construction for attaching the vertical ribs 34 to the channel piece 24. In Fig. 9 the upper end of the ribs 34 are riveted to the side of the channel piece 24, the channel piece 24 being made of smaller lateral cross-section to lit snugly within the channel member l0 of the chair frame. In Fig. 10 the cross member 24 is slotted at spaced-apart points along its bottom to receive therein the top ends of the strips 34 which are riveted to the side member much as in the manner shown in Fig. 9.

The invention is hereby claimed as follows:

1. A folding chair comprising a substantially U-shape frame, the lower portions of which form front legs, rear legs pivoted to said main frame, a seat pivoted to said frame and shiftably connected to said rear legs, and a full-length back for said chair comprising flexible members, said back being attached to the central portion of the U-shape frame and including a cross brace fixed to the lower ends of the flexible members, means shiftably rockably connecting said cross brace rearwardly of the longitudinal center of the rear legs whereby when the chair is folded the cross brace will clear a rearwardly projected portion.

2. A folding chair comprising a main frame adapted in open position to extend diagonally rearwardly in upright position, comprising front legs, a pair of rear legs pivotally connected to said main frame substantially intermediate its vertical length, a seat of curved contour pivotally connected to said front legs and shiftably connected to said rear legs and adapted to collapse and open with respect thereto, and a back extending from the top of said main frame downwardly and having its lower portion located adjacent the upper surface of the rear of the seat when the chair is in open position, said back being attached to the upper portion of said main frame and including a cross brace, means shiftably connecting said cross brace rearwardly or the longitudinal center of the rear legs whereby when the chair is folded the cross brace will clear a rearwardly projected portion.

3. A folding chair comprising an inverted U- shape frame, the lower portions of which form r front legs and the upper portion of which forms a back frame, a pair of rear legs pivotally connected to the upper portion of said rst frame, a seat pivotally connected to said frame and shiftably connected to said legs, said main frame and legs being oi channel shape construction, a sheet metal upper strip bent to U-shape sectional construction adapted to nest within the channel of the upper portion of the main frame, said strip having spaced slots therein, a plurality of spaced apart spring metal strips, each having an end in a slot in the upper strip, said end being fastened Within said upper strip, and a lower cross brace suitably slotted and having the lower ends of said spring metal strips disposed and fastened therein, said lower cross brace having a sheet metal lug attached at each end, each of said sheet metal lugs being slidably disposed in a channel of a rear leg member, said lower cross brace, when the `chair is in open position, lying substantially adjacentthe upper surface of the rear of the seat, and said spring metal strips providing a substantially full length back for the chair.

4. In combination, a substantially inverted U- shape member of channel shaped construction, the bottom portions forming legs, a lower brace interconnecting said legs, a pair of rear legs pivotally connected to the upper portion of said main frame, said legs being of channel shaped construction, a brace interconnecting said rear legs, a chair seat pivoted to said main frame and shiftably connected to said rear legs, a plurality of spaced apart, vertically extending spring metal strips having their upper ends connected to the horizontal length of the inverted U-shape frame member, a lower cross brace connected to the lower ends of said spring metal strips, and a pair of sheet metal lugs each having an aperture dis' posed rearwardly of the center of said lug, said cross brace having its end projecting through said aperture and fastened to said lug, said lug having its central portion provided with opposed substantially rounded portions and tapering toward each end to provide converging faces at each side thereof, each of said lugs being disposed in a channel of a leg whereby to permit said lugs and said lower cross member to slide longitudinally of said leg channel and to rock therein during the opening and closing movement of the legs and the seat.

5. A seat back adapted for attachment to the frame member and legs of a folding chair, comprising a sheet metal upper cross brace of substantially U-shape cross section having tapered upper surfaces adapted for insertion in the channeled horizontal reach of the main inverted U- v shape frame member of the chair and provided with spaced apart slots therein, a plurality of spring metal elongated vertically extending strips, each having an end disposed in a slot, with the end bent within said cross brace and fastened thereto, a lower cross piece of sheet metal suitably slotted, each slot adapted to receive the lower end of a spring metal strip, and means for fastening such ends thereto, the opposedends of the lower cross piece havingy fastened thereto a substantially diamond shaped lug, the corners of lthe lug being rounded to provide cam shaped faces to permit rocking and sliding movement of the lugs within the lchanneled leg portions` of a folding chair.

6. A seat back adapted for attachment to the frame members and legs of a folding chair, comprising a sheet metal upper cross brace of substantially U-shape cross section having tapered upper surfaces adapted for insertion in the channeled horizontal reach of the main inverted U-shape frame member of the .chair and provided with spaced apart slots therein, a plurality of spring metal elongated vertically extending strips, each having an end disposed in a slot, with the end bent within said cross brace and fastened thereto, a lower cross piece of sheet metal suitably slotted, each slot adapted to receive the lower end of a spring metal strip, and means for fastening such ends thereto, lthe opposed ends of the lower cross piece vhaving fastened thereto a substantially diamond shaped lug, the corners of the lug being rounded to provide cam shaped faces to permit rocking and sliding movement of the lugs within the channeled leg portions of a folding chair, said lug portions being formed of sheet metal and having their opposed ends acutely bent to provide sliding surfaces presentingY a minimum of friction.

7. A chair back comprising an upper cross member of substantially U-shape cross section having its upper opposed ends beveled, the lower portion of the channel shaped member along its length being provided with a plurality of spaced slots, a plurality of relatively long spring metal strips, each strip having its upper end passing through one of the slots and lying within the U-shape cross member and suitably connected thereto, a lower cross piece comprising a sheet metal strip bent upon itself and suitably slotted, each slot to receive the lower end of a spring metal strip, there being means for suitably connecting the same within the lower cross piece, each end of the lower cross piece having a sheet metal lug, said lug being substantially diamond shaped, the acute angles of the diamond shape being rounded to provide a. central thickened rocking portion and opposed pairs of diagonally disposed faces, each end of the lower cross piece passing through a slot in the lug and fastened thereto, said slot in the lug being laterally of the central longitudinal axis of the lug.

8. A folding chair comprising a main frame forming a back frame and front legs, a pair of rear legs each pivotally connected to the upper portion of the main frame, a seat of curved contour pivotally connected to the main frame and shiftably connected to the rear legs whereby to permit said legs and seat to collapse to adjacent folded position, and a full length back for said chair attached to the upper portion of the main frame and attached to the opposed rear legs adjacent the rear edge of the seat, said last mentioned attachment being shiftable to permit the opening and closing movement of the legs and seat and including a cross brace, means shiftably connecting said cross brace rearwardly of the longitudinal center of the rear legs whereby when the chair is folded the cross brace will clear a rearwardly projected portion of the seat.

9. A folding chair comprising a main frame forming an upper back frame and front legs, a pair of rear legs pivoted to the upper portion of said back frame, a chair seat pivotally connected to said main frame and shiftably connected to said rear legs whereby said seat and legs are adapted to collapse or to be opened, the seating surface of said seat extending rearwardly substantially to the rear legs in open position, a fulllength back for said back frame and rear legs,

said back comprising a plurality of relatively long, spaced-apart, spring metal strips and being attached to the upper portion of said upper frame, and means for slidably and rockably connecting said back to said rear legs, and including a cross brace, said spring metal strips being connected to the brace at their lower ends, means shiftably rockably connecting said cross brace rearwardly of the longitudinal center of the rear legs whereby when the chair is folded the cross brace will clear a rearwardly projected portion of the seat.

10. A seat back adapted for attachment to the frame member and legs of a folding chair comprising a plurality of spring metal, elongated, vertically extending strips, a lower cross brace, and a substantially diamond-shaped lug on each of the opposed ends of said lower cross brace, the lower ends of said spring metal strips being secured in spaced-apart relation to said lower cross brace, and the corners of saidlugs being rounded to provide cam-shaped faces to permit rocking and sliding movement of the lugs within the channeled leg portions of a folding chair.

11. A seat back adapted for attachment to the frame member and legs of a folding chair comprising a plurality of spring metal, elongated, vertically extending strips, a lower cross brace, and a substantially diamond-shaped lug on each of the opposed ends of said lower cross brace, the lower ends of said spring metal strips being se' cured in spaced-apart relation to said lower cross brace, said lower cross brace being located laterally rearwardly of the central longitudinal axis of said lugs, and the corners of said lugs beingV rounded to provide cam-shaped faces to permit rocking and sliding movement of the lugs within the channeled leg portions of a folding chair.

12. A folding chair comprising a main frame,

the lower portions of which form front legs for Y the chair, said main frame extending diagonally upwardly and rearwardly, a pair of channelshaped legs pivotally connected to said main frame slightly above the central portion of said main frame, aV seat pivotally connected to said front legs and shiftably connected to said rear legs, said legs and seat being adapted to collapse into juxtaposition and substantially into a single y plane, a back comprising a plurality of spring metal, elongated, vertically extending strips secured at their upper ends in spaced relation to said main frame and at their lower ends in spaced relation to a lower cross brace, a substantially diamond-shaped lug on each of the opposed ends of said lower cross brace, said lugs being slidably disposedin the channels of the rear leg members and the corners of said lugs being rounded to provide cam-shaped faces to permit rocking and sliding movement of the lugs within the channeled rear leg members, said lugs being formed of sheet metal and having their opposed ends acutely bent to provide sliding surfaces pressing against the inner faces of the channeled leg portions and presenting a minimum of friction producingrsurface against said channeled leg portions.

JAMES E. BALES. 

